A brushless DC electric motor of this type is known from EP-A-1 780 871. The winding of the stator is composed of a plurality of coils which are interleaved above each other and has a central axis of symmetry, which is also the axis of rotation of the rotor. The coils have four legs, wherein at least a section of each leg touches an edge of the adjacent winding. To produce the offsets at the regions of the two opposite corners of the coils, at each corner a hairpin-type bulge is necessary. Additional wire length is necessary to form the hairpin-type or loop-shaped bulge at an inner contour of the coils. Forming operation is required to complete a stator assembly.
U.S. Pat. No. 4,130,769 discloses a brushless DC motor, which has an armature coil body composed of a plurality of coils in a polygonal form of which at least two sides are placed parallel to the rotary axis of the motor. The coils are of planar shape and especially hexagonal or rectangular shape.
U.S. Pat. No. 6,355,993 discloses a linear motor having polygonal shaped coil units. The coils are arranged linearly and bonded to a substantially planar electrically insulating substrate.